20515 ÷ 8 = 2564 R3
Alright, let's work through the division of 20515 by 8 step by step.

Step 1:
8 goes into 2 0 times with a remainder of 2.
Write down 0 as next digit of of the result. 
Result so far: 0
Subtract 0 from 2 to get 2.
Bring next digit (0) of the dividend behind the 2 and repeat the process: 20 / 8

Step 2:
8 goes into 20 2 times with a remainder of 4.
Write down 2 as next digit of of the result. 
Result so far: 2
Subtract 16 from 20 to get 4.
Bring next digit (5) of the dividend behind the 4 and repeat the process: 45 / 8

Step 3:
8 goes into 45 5 times with a remainder of 5.
Write down 5 as next digit of of the result. 
Result so far: 25
Subtract 40 from 45 to get 5.
Bring next digit (1) of the dividend behind the 5 and repeat the process: 51 / 8

Step 4:
8 goes into 51 6 times with a remainder of 3.
Write down 6 as next digit of of the result. 
Result so far: 256
Subtract 48 from 51 to get 3.
Bring next digit (5) of the dividend behind the 3 and repeat the process: 35 / 8

Step 5:
8 goes into 35 4 times with a remainder of 3.
Write down 4 as next digit of of the result. 
Result so far: 2564
Subtract 32 from 35 to get 3.

The final result is 2564 with a remainder of 3.